Existing telecommunications networks, such as the public switched telephone network (PSTN) are typically configured so that equipment (such as switches) in the transmission, or bearer network, which carries user traffic (voice, video, and data signals), is co-located with equipment (such as signaling points) in the associated signaling network, which carries control signals for coordinating the operation of the bearer network.
However, telecommunications networks are migrating to a distributed architecture in which the equipment that carries user traffic is separated from the equipment that provides signaling functionality. Furthermore, a modern communication network typically comprises dissimilar networks that are coupled together. Such dissimilar networks can include, for example, the PSTN coupled to a packet network. These dissimilar networks generally employ different bearer technologies and/or signaling protocols.
Dissimilar telecommunications networks are typically interconnected via a “gateway” which provides the necessary conversions or adaptations between the bearer traffic and signaling protocol in each of the networks. In such an architecture an adaptation device, such as a media gateway (MG) (sometimes referred to as a “trunk gateway”) can be used to couple the dissimilar networks. A control device, such as a media gateway controller (MGC), provides control functionality over the media gateway, but need not be co-located with the media gateway. Generally, the media gateway passes voice and data information. A media gateway controller can communicate with one or more media gateways using a gateway control protocol, such as, for example, simple gateway control protocol (SGCP), media gateway control protocol (MGCP), Internet Protocol Device Control (IPDC), and H.218.
Typically, a media gateway and a media gateway controller are each coupled to both a PSTN and a packet network. The media gateway controller may communicate with other media gateway controllers over the PSTN using extensions of current call control protocols such as Signaling System No. 7 ISDN User Part (SS7 ISUP), Session Initiation Protocol (SIP—IETF RFC 2543), ITU Recommendation H.323, or Bearer Independent Call Control (BICC). New protocols may be defined for this interface in the future.
A media gateway controller communicates with a media gateway using, for example, MGCP. Accordingly, the media gateway does receive signaling messages, but they are from the media gateway controller. In addition, multiple media gateways may communicate with each other using what is referred to as a “gateway-to-gateway” protocol. Examples of gateway-to-gateway protocols are H.323 and the SIP protocol. Alternatively, other non-standard gateway-to-gateway protocols may be used, depending on the manufacturer of the media gateway.
When user traffic, such as a telephone call occurring between a node located in the PSTN and a node located in the packet network, spans the dissimilar communication networks, the user traffic is identified differently by the two communication networks.
Further, today's modern telephony and internet Protocol (IP) multiple service networks use a variety of protocols to provide many different functions to enable delivery of services to network users. Protocol monitoring applications, such as those that enable tracing across a signaling network the protocol messages associated with a call, or building a call data record (CDR) to summarize the key parameters relating to user traffic (i.e., a telephone call), require the ability to map call identifiers across different protocols, which may refer to a single entity in multiple different, inconsistent ways.
Therefore, it would be desirable to have a network analysis device that is capable of correlating two or more different communication signaling protocols relating to the same user traffic in a communication network that comprises at least two dissimilar communication networks, or two dissimilar communications signaling protocols within one communication network, and that displays this information in real time to a user of the network analysis device.